Currently, a projection display system based on the digital light processing (DLP) technologies is often a projection display system using a single digital micromirror device (DMD), if a single DMD is used, the light source utilization efficiency can be low. A single-DMD projection display system is shown in FIG. 1, where 10′ is a video source, 20′ is a video decoding circuit, 30′ is a DMD driving circuit, 40′ is a color wheel driving circuit, and 50′ is a DMD.
The operation process of the single-DMD projection display system is: the video source 10′ outputs video data, and the video decoding circuit 20′ decodes the video data into three color component data of red (R), green (G), blue (B), which is then outputted to the DMD driving circuit 30′. The DMD driving circuit 30′ has three channels including a red data channel (R channel), a blue data channel (B channel), and a green data channel (G channel), as well as a clock & control data channel (CLK&CTL channel). The R channel receives a red component data signal, the B channel receives a blue component data signal, the G channel receives a green component data signal, and the CLK&CTL channel receives a clock & control signal. Based on a color wheel feedback signal of the color wheel driving circuit 40′, the DMD driving circuit 30′ time-sparingly outputs component data of red, green, blue, etc. to the DMD 50′ for display according to a specific timing sequence. In the projection system, for the DMD, an average display time of one color may only be one third of a unit of time. Accordingly, the efficiency for displaying images using the projection display system is low, resulting in a relatively low image brightness.
Currently, there is no effective solution yet to solve the low efficiency issue in displaying images using the existing projection display system.